System tube and process for supporting cylindrical elements of an endoscope optical system
A system tube of an endoscope optical system, designed to contain cylindrical elements of an image guide provided with lenses and to support the elements by tongues cut out of the wall of the system tube and deformed nonelastically. Wherein the tongues are deformed toward the outside and are bent elastically by a holder toward the inside to below the level of the outer surface of the system tube. In a system tube of an endoscope optical system, designed to contain cylindrical elements of an image guide provided with lenses and to support the elements by means of nonelastically deformed tongues cut out of the wall of the system tube, the tongues are deformed toward the outside and are elastically bent by a holder toward the inside to below the level of the outer surface of the system tube.
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The present application is based upon and claims the benefit of priority from DE 10 2011 008 105.4 filed on Jan. 10, 2011, the entire contents of which is incorporated herein by reference.
BACKGROUND1. Field
The present invention generally relates to an endoscope optical system and more particularly to a system tube of an endoscope optical system and a process for retaining cylindrical elements.
2. Prior Art
An endoscope optical system has an image guide which transfers the image from a distally disposed objective to a proximally disposed viewing device, e.g., an ocular or a video camera. In designs of this class, the image guide is provided with lenses which are packed behind each other in a system tube, optionally with spacing tubes in between, and guided into the optically correct position by it (the system tube). The system tube usually consists of metal.
In this process it is necessary to make sure that the lenses are firmly retained in the system tube so that their position cannot change in case of shaking, which would lead to a disturbing jumping of the viewing direction.
In the case of system tubes of this type, tongues are cut out from the wall of the system tube and deformed nonelastically, permitting the reliable and solid support of the cylindrical elements of the image guide, thus the lenses and optionally also the spacers.
DE 10 2006 041 920 A1 shows a system tube of this type in which the tongues are deformed nonelastically toward the inside. This leads to a constriction of the free cross-section in the area of the tongues, by means of which cylindrical elements disposed in the system tube are reliably clamped or can be guided with low play. Securing of the image guide against rattling of its elements with resulting jumps in the image direction is achieved reliably. However, this known design also has considerable drawbacks. During the insertion of the elements of the image guide into the system tube, clamping forces must be overcome. This interferes with the fine adjustment of the elements. An additional considerable drawback occurs during disassembly, thus when the cylindrical elements of the image guide must be removed again from the system tube. They must then be slid with force from the area of the clamping tongues, which can lead to problems, e.g., to damage.
Patent DE 197 50 685 A1 shows a system tube of an endoscope optical system, wherein openings are provided in the wall of the system tube through which adhesive is introduced in the form of adhesive dots to retain the lenses disposed in the system tube.
DE 197 32 991 A1 shows a system tube in the wall of which beads are disposed, wherein the system tube is deformed toward the inside by these beads and thus lies adjacent to cylindrical elements disposed in the system tube.
The goal of the present invention consists of simplifying the assembly and disassembly of the elements of the image guide in a system tube of the relevant class.
SUMMARYAccording to the invention the tongues are nonelastically deformed toward the outside, specifically such that they can be bent elastically towards the interior to below the level of the outer surface of the system tube, thus the level at which these lugs were positioned prior to the nonelastic deformation. The lugs are pressed in with any suitable holder, e.g., with the thumbs. Even if the point of the lug located farthest to the outside with regard to the axis of the system tube is exactly at the radial distance which it occupied prior to the nonelastic deformation, thus at the original level of the surrounding system tube, retention by clamping force of the cylindrical element, located at this point, a lens or a spacer tube located with the usual low play in the system tube, results. Thus, the invention utilizes the recognition that a lug that is bent nonelastically out of a wall of the tube, upon bending back cannot be brought back exactly into its original position, thus the position before the nonelastic deformation. This results from changes in shape of the lug, occurring during the nonelastic deformation, which cannot be eliminated by elastic restoration. These ensure that if outer points of the lug are pressed back to the original level, internal points of the lug are pressed back into the interior space of the system tube, thus project within the level of the inner surface of the system tube, and clamp the cylindrical elements in place there.
Since the tongues are pressed down elastically, upon removing the holder they return toward the outside in their position established by the nonelastic deformation. Thus the cylindrical elements disposed in the system tube, in the absence of the holder, are free and movable with low forces. They can then be easily filled in, adjusted and removed. With the holder in place, the elements are held firmly by the tongues. After removal of the holder, the elements are free again and can be easily removed.
Any suitable objects can be used as holders, for example the thumbs of the person doing the assembly, performing a trial fixation. Advantageously according to claim 2, a sleeve tube that can be slid over is used as a holder, which usually already surrounds the system tube, generally in the form of the so-called fiber tube or in the form of a tube forming the outer surface of the endoscope in the case of a very simple endoscope optical system without illumination.
The nonelastic deformation of the tongues in the direction toward the outside requires a tool that grasps the tongues from the inside. This operation can operate, for example, with a long shaft passing through the tube, for example in the form of a forceps-like design with spreadable jaws and a long shaft. Preferably according to claim 3, however, the system tube has openings located opposite the tongues, through which they can be pressed conveniently and over a short distance, for example with a straight pusher.
A system tube can consist of various materials that are suitable based on their material properties, thus are nonelastically deformable and after this, remain elastically flexible. A number of plastics are suitable for this. Preferably according to claim 4, however, the system tube consists of metal, which has already been proven advantageous for this purpose in endoscope optical systems.
Claims 5 to 7 pertain to advantageous methods for retaining cylindrical elements of an image guide in a system tube of the endoscope.
In the drawings, the invention is shown by way of example and systematically, in which:
The lenses 8 can, as shown, be designed as elongated rod lenses or also as short lenses, in which the problems of tipping are substantially more serious than in the case of long lenses. Instead of individual lenses, lens sets may be provided, which for example may be assembled in a tube.
If a lens 8 according to
This tube 9 is moved relative to the system tube 1. For this purpose in the exemplified embodiment shown it is slid over the system tube 1 in the direction of the arrow 10. It can also remain in place and the system tube be slipped in.
In this process the sleeve tube 9 presses the tongue 2 out of the position according to
As
it has become longer as a result of the nonelastic deformation and no longer fits into its cutout in the system tube 1. It is also nonelastically deformed and thus has permanent deformations that no longer fit into the original form of
A necessary result is that the tongue 2, held on the outer circumference of the system tube 1 by its radially farthest outside lying point 11, must now lie with parts inside the inner circumference of the system tube 1, as shown in
Since the bending of the tongue 2 from the position according to
Here, elastic bending is also defined as an essentially elastic bending which has nonelastically deforming fractions. The above explanations also apply for this case.
A tongue 16 corresponds to the parallel cuts of the embodiment of
The different tongue shapes shown for example in
In
In reference to the longitudinal direction of the system tube 1, the tongues, as shown in
While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims.
Claims
1. A system tube of an endoscope optical system, the system tube comprising:
- a cylindrical body having a longitudinal axis and a wall formed around the longitudinal axis of a material capable of being nonelastically deformed, the wall defining an interior and the wall having one or more nonelastically deformed tongues formed by cuts made in the wall, the one or more tongues being deformed in a radially outward direction from the longitudinal axis;
- cylindrical elements of an image guide provided with one or more lenses; and
- a holder disposed over the cylindrical body, the holder having an inner dimension which radially interferes with the one or more tongues such that the one or more tongues are deformed radially inward into the interior to secure the cylindrical elements within the cylindrical body.
2. The system tube according to claim 1, wherein the holder is formed as a sleeve tube wherein the inner dimension is an inner diameter larger than an outer diameter of the cylindrical body and smaller than a cross-sectional dimension of the cylindrical body at a location of the one or more tongues.
3. The system tube according to claim 1, wherein the cylindrical body includes an opening corresponding to each of the one or more tongues, the opening being formed on the wall of the cylindrical body at a position radially opposite to the corresponding one or more tongues.
4. The system tube according to claim 2, wherein the cylindrical body includes an opening corresponding to each of the one or more tongues, the opening being formed on the wall of the cylindrical body at a position radially opposite to the corresponding one or more tongues system.
5. The system tube according to claim 1, wherein the cylindrical body is made of metal.
6. The system tube according to claim 2, wherein the cylindrical body is made of metal.
7. The system tube according to claim 3, wherein the cylindrical body is made of metal.
8. A method for holding cylindrical elements of an image guide provided with one or more lenses in a system tube of an endoscope, the method comprising:
- cutting one or more tongues in a wall of a cylindrical body forming the system tube; and
- nonelastically deforming the tongues in a radially outward direction from a longitudinal axis of the cylindrical body; and
- radially deforming the one or more tongues inward into an interior of the cylindrical body to secure the cylindrical elements within the cylindrical body.
9. The method according to claim 8, wherein the radially deforming comprises sliding a holder over the cylindrical body to provide a radial interference between the one or more tongues and an inner dimension of the holder.
10. The method according to one of claim 8, wherein the nonelastically deforming of the one or more tongues comprises pushing the one or more tongues radially outward from an opening formed on the wall of the cylindrical body at a position radially opposite to the one of more tongues.
11. The method according to one of claim 9, wherein the nonelastically deforming of the one or more tongues comprises pushing the one or more tongues radially outward from an opening formed on the wall of the cylindrical body at a position radially opposite to the one of more tongues.
4148550 | April 10, 1979 | MacAnally |
6201649 | March 13, 2001 | Rudischhauser et al. |
6398723 | June 4, 2002 | Kehr et al. |
7660052 | February 9, 2010 | Scholer |
20080062540 | March 13, 2008 | Scholer |
Type: Grant
Filed: Jan 10, 2012
Date of Patent: Jan 21, 2014
Patent Publication Number: 20120176669
Assignee: Olympus Winter & IBE GmbH (Hamburg)
Inventor: Gregor Kiedrowski (Hamburg)
Primary Examiner: Mahidere Sahle
Application Number: 13/346,897
International Classification: G02B 7/02 (20060101);